## andriod09 Group Title Quadratic Equation question How do i get from: $x=-11\pm \frac{121-60}{ 6 }$ to the next part? one year ago one year ago

1. andriod09 Group Title

@jwheele1

2. jwheele1 Group Title

ok

3. cos00155079 Group Title

im working on those problems too im not that good but i would simplify 121-6/ then.. which is?

4. jwheele1 Group Title

well first of all.....write out two different equations to eliminate that +-

5. andriod09 Group Title

@cos00155079 you doing the Life of Fred series?

6. andriod09 Group Title

you don't have to do that @jwheele1

7. jwheele1 Group Title

i know you dont have to but its easier...its cool we wont do that then

8. cos00155079 Group Title

the what? nooo...

9. jwheele1 Group Title

121 - 60 = ?

10. andriod09 Group Title

61

11. andriod09 Group Title

10

12. andriod09 Group Title

$1$ $-21$

13. cos00155079 Group Title

why 60/6 if it was a 61?

14. andriod09 Group Title

ik

15. jwheele1 Group Title

alright lets see now...

16. andriod09 Group Title

the equation is: $x=-11\pm \frac{ \sqrt{121-60} }{ 6 }$

17. jwheele1 Group Title

oh lawd....lol

18. jwheele1 Group Title

sq rt of 121 = 11

19. jwheele1 Group Title

whats with teh line over the 0?

20. andriod09 Group Title

its just how it is. not my doing.

21. jwheele1 Group Title

well...it means that its a repeating number but its usually only after a decimal point...weird.

22. jwheele1 Group Title

I have no idea what to do with the 60 and the line over it.

23. andriod09 Group Title

the original equation is: $3x^{2}+11x+5=0$

24. jwheele1 Group Title

any specific way she is wanting you to go about that?

25. andriod09 Group Title

its a messup about square roots.

26. jwheele1 Group Title

or can we solve for x any old way?

27. andriod09 Group Title

yea, using $ax^{2}+bx+c=0$ and the $x=-b\pm\frac{ \sqrt{b^{2}-4ac} }{ 2a }$

28. jwheele1 Group Title

29. jwheele1 Group Title

ok so 3x^2 + 11x +5 = 0 ax^2 + bx +c

30. jwheele1 Group Title

a = 3 b = 11 c = 5

31. jwheele1 Group Title

$-11\pm \frac{ \sqrt{11^{2}-4(3*5c)} }{ 2(3) }$

32. jwheele1 Group Title

does that look right?

33. jwheele1 Group Title

ignore the c next to the 5, lol |dw:1348620564257:dw|

34. jwheele1 Group Title

|dw:1348620625370:dw|

35. jwheele1 Group Title

i see where we screwed up now in the beginning

36. jwheele1 Group Title

|dw:1348620687638:dw|

37. jwheele1 Group Title

NOW......what has your teacher said to do with this?

38. jwheele1 Group Title

because you can find common denominaters and put it all over one bar or you can leave it the way it is.

39. andriod09 Group Title

I teach my self. I am homeschooled, i use the LoF series.

40. jwheele1 Group Title

oh, cool

41. jwheele1 Group Title

well....you could work it out to this way if you wanted to.... |dw:1348620830185:dw|

42. andriod09 Group Title

the last answer i got was $x_{1}$ and $x_{2}$

43. jwheele1 Group Title

OH yeah...i forgot this was all part of an original equation....this one might be too complicated for the quad formula. have you tried grouping method?

44. jwheele1 Group Title

i mean factoring

45. andriod09 Group Title

and it was $x=\frac{-9\pm7} { 8 }$ I did the quadratic formula on all of these so far, its a quadratic formula page. they're supposed to use the quadratic formula

46. jwheele1 Group Title

ok well then we must find exact values

47. jwheele1 Group Title

the sq rt of 61 is 7.810249675906654

48. jwheele1 Group Title

divided by 6 = 1.301708279317776

49. jwheele1 Group Title

-11 + 1.301708279317776 = ? -11 - 1.301708279317776 = ?

50. andriod09 Group Title

we need not find exact values, we need to find $x_1$ and $x_2$

51. jwheele1 Group Title

x1 and x2 are exact values

52. jwheele1 Group Title

it appears anyways...this one is ugly

53. jwheele1 Group Title

x1 = -9.698291720682224, x2 = -12.30170827931778 lol

54. jwheele1 Group Title

none of this seems right to me and its driving me nuts, lol

55. jwheele1 Group Title

for sure you need to find the square root of 61

56. jwheele1 Group Title

which is not what you have in your original problem at the top

57. jwheele1 Group Title
58. jwheele1 Group Title

59. jwheele1 Group Title

60. andriod09 Group Title

its these: $x_{1}=\frac{ -11+\sqrt{61} }{ 6 }$ and $x_{1}=\frac{ -11-\sqrt{61} }{ 6 }$

61. jwheele1 Group Title

thats what i would put....what you just put

62. andriod09 Group Title

this is what my brother says, who is in college.

63. jwheele1 Group Title

i am also in college. I woudl also stop there...I thought it was weird that were were trying to find the actual value for x1 and 2

64. andriod09 Group Title

|dw:1348621589793:dw|

65. jwheele1 Group Title

That is if you put it all under one common denominator which some teachers ask for...usually that is not what they want though

66. jwheele1 Group Title

it means the same thing but most people show it liek yoru brother did

67. andriod09 Group Title

w/e i have it and its done. thanks for any help!

68. jwheele1 Group Title

yw